Petroleum oil compositions



Patented May 13, 1947 UNITED STTES ATENT PETROLEUM 01L COMPOSITIONS NoDrawing. Application November 26, 1945, Serial No. 630,984

3 Claims.

This invention relates to novel petroleum oil compositions containingstabilizers and more particularly to mineral oil compositions thatcontain an inhibitor effective to retard halogenation thereof.

It is well known that petroleum oils can be chlorinated. However, thereare some situations in which it is desired to employ a, petroleum oilwhere it will be in contact with gaseous chlorine and still not reacttoo extensively therewith. This problem arises for instance inconnection with the operation of gas compressors and vacuum pumps usedto handle gases containing chlorine. In such gas compressors and vacuumpumps petroleum lubricating oils are employed not only to lubricate andto cool the pump mechanism but also to provide a liquid. seal whichassists in maintaining the pressure or vacuum. When such compressors andvacuum pumps are employed to handle gases containing chlorine, thepetroleum lubricating oils used to facilitate the operation of saidcompressors and pumps tend to become chlorinated. The chlorination ofsaid petroleum lubricating oils is disadvantageous, since when said oilsare chlorinated their viscosities increase greatly, and decompositionproducts are formed; hence their effectiveness as mediumsforlubricating, cooling and maintaining liquid seals in gas compressors andvacuum pumps becomes greatly diminished.

It is accordingly an object of this invention to provide suitable liquidmediums capable of lulbrieating, cooling and maintaining liquid seals ingas compressors and vacuum pumps, the effectiveness of which will notsubstantially diminish if said gas compressors and vacuum pumps areused' to handle gases containing chlorine. A further object is toprovide improved mineral oil compositions, the viscositles of which donot rapidly and greatly increase when said mineral oil compositions comein contact with gaseous chlorine and which are otherwise stable in thepresence of chlorine under the conditions of use. A still further objectis to provide a stabilized mineral oil composition containing aninhibitor effective to retard chlorination thereof. Another object is toprovide a mineral oil composition containing an inhibitor capable ofreducing the susceptibility of said mineral oil to chlorination, whichoil composition can be reclaimed after use by treating it with clayWithout any substantial loss of its ability to resist chlorination.Other objects will appear hereinafter.

These objects are accomplished in accordance with the followinginvention by providing a mineral oil composition comprising a majoramount of a petroleum lubricating oil and a minor amount of benzaldehydephenylhydrazone sufiicient to retard halogenation of said petroleumlubricating oil. This invention is applicable to both paraffinic andnaphthene-type lubricating oils. It is particularly applicable tolubricating oils having a viscosity ranging from to 450 SayboltUniversal seconds at 100 F. Ordinarily the addition of from 0.25 to 0.5per cent by weight of benzaldehyde phenylhydrazone to such an oil willsuffice to substantially reduce the susceptibility of the oil tochlorination.

It has been found that a petroleum lubricating oil which has been highlyrefined in the presence of anhydrous aluminum chloride and which has ahigh viscosity index of the order of 100 and a viscosity of aboutSaybolt Universal seconds at 100 F. is a very efiective lubricant for avacuum pump. However, if said pump is used to handle gases containingchlorine this lubri cating oil deteriorates greatly and its viscosityincreases greatly. A mineral oil composition containing 0.5 per cent byweight of benzaldehyde phenylhydrazone added to a petroleum lubrieatingoil having the properties just mentioned is not readily attacked bychlorine. When this oil composition containing benzaldehydephenylhydrazone is used to lubricate and facilitate the operation of avacuum pump that is handling gases containing chlorine, it does notreadily deteriorate and its viscosity increases slowly in smallincrements.

It has also been found that the addition of benzaldehyde phenylhydrazoneto a mineral oil lubricant materially improves its color stability.

Furthermore, it has been found that petroleum lubricating oils containinbenzaldehyde phenylhydrazone as a, chlorination inhibitor can bereclaimed by heating them with fullers earth and that the reclaimed oilsare still resistant to chlorination. This is important because it is aroutine operationto reclaim vacuum pump oils by passing them through afullers earth filter at 210 to 220 F. Persistence of the inhibitingeffect after said clay treatment is obviously very desirable when theoils are to be used after reclaiming in places where they will come incontact with chlorine.

In determining whether a given oil composition containing a known amountof a chlorination inhibitor can be heated with clay as is done in an oilreclaiming operation without substantial loss of its ability to resistchlorination, the following experimental procedure is employed.

Ten per cent by weight of powdered fullers earth is added to an oilcomposition containing a chlorination inhibitor at temperatures between210 and 220 F. to drive oif any water, and the oil is stirred vigorouslyfor ten minutes. The mixture is then immediately filtered twice with thehelp of an asbestos type of filter aid. The oil composition thus treatedmay then be tested by the procedure set forth in the following paragraphto see if it is sufficiently stabilized against chlorination.

In determining whether a given oil composition containing a known amountof a chlorination inhibitor is sufficiently stabilized againstchlorination, the following experimental procedure is employed. Aplurality of 80 c. 0. samples of the oil composition containing aninhibitor are placed in 100 c. c. graduated cylinders, and 8 c. c. ofdistilled water is added to each cylinder. Each of the samples is shakenvigorously, and 12 inches each of No. 20 American gauge copper and ironwires coiled together are immediately introduced into each cylinder,being suspended in the emulsion from the top of each cylinder. Freegaseous chlorine is then bubbled through each sample at the rate of 1400c. 0. per hour. At hourly intervals chlorination of one of the samplesis discontinued, and the copper and iron wires are removed therefrom.After chlorination has been discontinued on a given sample it is allowedto sit until the oil reaches room temperature. The oil is decanted fromthe water and then blown with free nitrogen until all free chlorine hasbeen eliminated. It is usually necessary to blow with nitrogen for abouttwo hours before the oil no longer emits an odor of chlorine. Eachsample is then analyzed to find the amount of chlorine taken up by theoil, and its viscosity is determined by A. S. T. M. method'D 88-44. Inthis way one can determine the amount of chlorine absorption and theviscosity change at hourly intervals, and these data can be plotted incurves if desired.

When a petroleum lubricating oil that has been refined in the presenceof anhydrous aluminum chloride, which has a viscosity index of about 100and a viscosity of about 170 Saybolt Universal seconds at 100 F., andwhich contains no inhibitors is chlorinated and tested in accordancewith the procedure set forth in the preceding paragraph, it is foundthat after five hours of chlorination it has absorbed 11.3 per cent ofchlorine and its viscosity in Saybolt Universal seconds at 100 F. hasincreased 135 per cent. When to the same oil there is added 0.5 per centby weight of benzaldehyde phenylhydrazone, it is found that after fivehours oi. chlorination it has absorbed only 5.3 per cent of chlorine andits viscosity in Saybolt Universal seconds at F. has increased only 28per cent. Furthermore, when the same oil containing 0.5 per cent byweight of benzaldehyde phenylhydrazone has been heated with fullersearth as described hereinabove, it is found that after five hours ofchlorination it has absorbed only 5 per cent of chlorine and itsviscosity in Saybolt Universal seconds at 100 F. has increased only 30per cent. It can therefore be seen that benzaldehyde phenylhydrazonematerially retards chlorination of this lubricating oil.

Resort may be had to such variations and equivalents of this inventionas come within the spirit of the invention and the scope of the appendedclaims.

What we claim is:

1. A mineral oil composition comprising a major amount of a petroleumlubricating oil and a minor amount of benzaldehyde phenylhydrazonesuflicient to retard halogenation of said petroleum lubricating oil.

2. A mineral oil composition comprising a major amount of a petroleumlubricating oil having a viscosity lying in the range from about to 450Saybolt Universal seconds at 100 F. and from 0.25 to 0.5 per cent byweight of benzaldehyde phenylhydrazone to retard chlorination of saidpetroleum lubricating oil.

3. A mineral oil composition suitable for facilitating the operation ofa vacuum pump that is handlin gases containing chlorine comprising about99.5 per cent of a highly parafiinic petroleum lubricating oil having aviscosity of about 1'70 Saybolt Universal seconds at 100 F., and about0.5 per cent of benzaldehyde phenylhydrazone to retard chlorination ofsaid petroleum lubricating oil.

ALBERT G. ROCCI-IINI. CHARLES BYRON PATTINSON, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,339,984 Eitelman Jan. 25, 19442,322,184 White June 15, 1943 1,492,391 McQuade Apr. 29, 1924

